Many couldn’t imagine a life without it, but as well as keeping us all connected, Facebook may actually be spreading unhappiness through society, researchers have claimed.

Psychologists have claimed the hugely popular social network, which boasts over one billion active users, is strongly associated with declines in well-being.

A study, printed in the journal Public Library of Science ONE, found the more time people spent on Facebook over two weeks, the worse they subsequently felt.

In contrast, those who met with their friends in person or spoke to them on the phone showed greater levels of happiness.

Dr Ethan Kross, from the University of Michigan, who led the study, said: ‘On the surface, Facebook provides an invaluable resource for fulfilling the basic human need for social connection.

‘But rather than enhance well-being, we found that Facebook use predicts the opposite result – it undermines it.’

During the study, 82 young adults were sent questions by text message at five random times each day for two weeks.

Participants were asked how they felt ‘right now’, how worried or lonely they were, and to what extent they had been using Facebook or interacting with other people directly.

The researchers said they found higher levels of Facebook use correlated with greater loss of well-being.

The volunteers were also asked to rate their level of life satisfaction at the start and end of the study. Over the two-week period, satisfaction ratings were found to decline the more people used Facebook.

Commenting on the results, University of Michigan neuroscientist and co-author Dr John Jonides said: ‘This is a result of critical importance because it goes to the very heart of the influence that social networks may have on people’s lives.’

There was no evidence that people were more likely to log into Facebook when they felt bad, said the researchers. In addition loneliness and Facebook both had an independent impact on happiness.

‘It was not the case that Facebook use served as a proxy for feeling bad or lonely,’ said Dr Kross.

Further research is planned to look at the psychological reasons for the negative effect of Facebook on well-being.